After leaving the Hospital Wing, Harry spent the whole way discussing Diggory with Hermione and Ron. It seemed strange no matter how he looked at it that Diggory had come to Hogwarts to be hospitalized. St. Mungo's Hospital for Magical Maladies and Injuries would have been the better choice, yet Diggory had come to Hogwarts.
The three of them ultimately agreed that the main reason Diggory had come to Hogwarts to recover was because Hogwarts was safe. After all, people had been disappearing from St. Mungo's Hospital for Magical Maladies and Injuries recently, and there was still not the slightest clue as to what had happened to them.
As for why Diggory had been injured, that was still a mystery. But all three believed his injuries were connected to The Dark Lord. Otherwise, Diggory would not have come to Hogwarts... to seek refuge.
In short, the whole affair seemed strange no matter how they looked at it. Anyone with half a functioning brain could tell something was wrong.
After discussing it, they decided to use the Communication Bookmark to see whether they could contact Fred and George that way.
If possible, Harry wanted to talk to them in person. The Communication Bookmark could only relay a limited number of words, making it difficult to explain himself clearly.
Fortunately, by mid-October, Hogwarts third-years would be allowed to visit Hogsmeade. They could arrange to meet then.
"By the way, Harry, Professor Slughorn asked me to tell you there's a gathering this Wednesday evening. He hopes you can attend."
While Ron was in the Boys' Lavatory, Hermione brought up the Slug Club invitation with Harry.
She actually knew why Harry had not gone, but there were things she still needed to tell him. Besides, Harry seemed to intend to get some secrets out